SEOUL, South Korea — North Korea may be getting closer to designing an intercontinental ballistic missile that could eventually carry a nuclear warhead to a target such as the mainland United States, two weapons analysts said.

Missiles paraded in Pyongyang in July appear more genuine than models shown in April 2012, which were widely dismissed as fakes.

The missiles are similar in appearance to the long-range rocket the North launched last year to put a satellite into orbit, Jeffrey Lewis and John Schilling wrote on 38 North, a blog run by the U.S.-Korea Institute at Johns Hopkins University’s School of Advanced International Studies.

“These are more like the sort of mock-ups engineers build when they are confident in their design, ready to start testing on the ground before committing to flight,” Lewis, a non- proliferation analyst, and Schilling, an aerospace scientist, said. “It is not unusual for countries to build mock-ups or simulators of missiles as an early step in the process of developing new ballistic missiles.”

In March, North Korea threatened to attack the United States with nuclear missiles, one month after it conducted its third atomic test.

The Obama administration contends the North doesn’t have the ability to tip a long-range missile with a nuclear warhead.